Thanks for the code – would you be willing to contribute it under the MIT license?
On Tue, Feb 10, 2015 at 9:21 AM, Dawid Crivelli <[email protected]> wrote: > I have a short code for checking the sign of a permutation for personal > use. It's O(L^2) where L is the length of the permutation vector, but it's > perfectly fine for L in the few tens range. > > function sign{T<:Integer}(perm::AbstractVector{T}) > L = length(perm) > crosses = 0 > for i = 1:L > for j = i+1 : L > crosses += perm[j] < perm[i] > end > end > return iseven(crosses) ? 1 : -1 > end > > >
